JP2691448B2 - Shaft sealing device for fluid machinery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shaft sealing device, and particularly to a shaft sealing water for a fluid machine, which is suitable for completely sealing the shaft even if a rotation shaft or the like is displaced. Regarding the device.

[Conventional technology]

In a conventional shaft sealing device for a fluid mechanism, as shown in FIGS. 2 and 3, an upper cover 2 fixed to an inner peripheral wall of a casing 1 and a rotating shaft 3 inserted through a center of the casing 1. It is provided in the annular space between.

A tubular stationary outer ring 4 having one end (lower side) end face fixed to the upper cover 2, and an outer circumference fixed to the other end (upper side) end face of the stationary outer ring 4 to rotate the inner circle. 3 and an annular stationary-side auxiliary seal ring 8 formed concentrically with the rotary shaft 3 which is slidably contacted in the axial direction through a water-sealing material 9 provided on the inner circle.
A stationary-side inner ring 10 positioned substantially concentrically with the stationary-side inner ring 10, and a stationary-side sealed ring 11 attached to one end surface (lower side) of the stationary-side inner ring 10,
A rotating side sealing ring 13 which is in sliding contact with the stationary side sealing ring 11 to form a sealing end face 12 and which is attached to one side (lower side) of the rotating shaft 3.
And a stationary side outer ring 4, a stationary side auxiliary sealing ring 8, a stationary side inner ring 10, a stationary side sealing ring 11 and a sealing chamber 14 surrounded by a rotating side sealing ring 13, respectively. And the stationary inner ring 10
And a spring 31 between the stationary side sub-sealing ring 8 and the pressing bolt 32 screwed to the stationary side sub-sealing ring 8 to urge the spring 31 to press the sealing end face 12 and to seal the liquid in the sealing chamber 14 to seal the sealing end face. It was configured to cool the 12 and keep the hermetically sealed end face 12 airtight. This structure is described in JP-A-57-190165. The stationary inner ring 10 is rotationally locked to the stationary sub-sealing ring 8 by a key 30, and the fluid flowing from the casing 1 passes through the guide vanes 5 and the runner 6
The pressure is increased by and is discharged from the discharge pipe 7.

The guide vanes 5 are closed when the fluid machine is stopped, and are opened when the fluid machine is started, whereby fluid pressure is applied to the lower surface of the upper cover 2 and the upper cover 2 bends downward. That is, during the operation of the fluid machine, the flexure of the flexure angle θ is repeatedly received with the outer peripheral side Q of the upper cover 2 as a fulcrum, so that the expansion and contraction of the spring 31 reduces the surface pressure of the sealing end face 12 and the liquid inside the sealing chamber 14 Will come out.

Further, there is also a problem that the spring 31 expands and the surface pressure of the sealing end face 12 decreases due to the axial displacement of the rotary shaft 3 toward the upper side due to the fluid pressure, and the liquid in the sealing chamber 14 leaks. .

[Problems to be solved by the invention]

In the conventional shaft sealing device for fluid machinery, since the upper cover or the rotating shaft is displaced by the pressure of the fluid, the spring expands and contracts, the surface pressure of the sealing end face decreases, and the liquid in the sealing chamber leaks. There was a problem.

An object of the present invention is to provide a shaft water sealing device for a fluid machine in which fluid in the sealed chamber does not leak due to displacement of the upper cover or the rotating shaft, respectively.

[Means for solving the problem]

In order to achieve the above object, a shaft sealing device for a fluid machine according to the present invention is provided in an annular space between an upper cover fixed to an inner peripheral wall of a casing and a rotating shaft inserted through the center of the upper cover, A tubular stationary outer ring with one end surface fixed to the upper cover, and an annular stationary auxiliary ring with the outer circumference fixed to the other end surface of the stationary outer ring and the inner circumference being concentric with the rotating shaft. A sealing ring, and a stationary inner ring which is slidably contacted in the axial direction via a water sealing material provided on the inner peripheral surface of the stationary side sub-sealing ring and is concentric with the rotating shaft via a gap. A stationary side seal ring attached to one end surface of the stationary side inner ring, and a rotating side seal ring that is in sliding contact with the stationary side seal ring to form a sealed end surface and is attached to one side of the rotary shaft. Stationary side outer ring, stationary side sub-sealing ring,
In a shaft sealing device for a fluid machine, which comprises a stationary side inner ring, a stationary side sealing ring, and a sealed chamber surrounded by a rotating side sealing ring, the other of the bearing supporting ring fixed to the other side of the rotating shaft and the stationary side inner ring. The pressing mechanism is provided between the bearing ring and the supporting ring that contacts the end face on the side, and the pressing mechanism slidably contacts the bearing supporting ring and the bearing, and presses the stationary inner ring through the supporting ring. It is configured to include an elastic mechanism that presses the stationary side seal ring against the rotating side seal ring.

The pressing mechanism includes a sliding ring that slidably contacts the bearing, a support ring that is provided to face the sliding ring and that contacts the other end surface of the stationary inner ring, and one end of the sliding ring. It is composed of at least one piston which is fixed and whose other end is attached to a supporting ring through an elastic mechanism, and an adjusting mechanism which adjusts the urging force of the elastic mechanism.

Further, the elastic mechanism may be a spring and may be a hydraulic cylinder or a hydraulic cylinder.

[Action]

According to the present invention, the stationary side sealing ring is pressed against the rotating side sealing ring via the stationary side inner ring by providing the pressing mechanism in the shaft water sealing device for a fluid machine. Therefore, when the upper cover or the rotating shaft is displaced in the axial direction by the pressure of the fluid, the stationary side sub-sealing ring slides axially on the outer surface of the stationary side inner ring through the sealing material, and the stationary side sub-sealing ring becomes Since it does not engage with the stationary side inner ring, it does not change to the surface pressure of the sealing end surface.

〔Example〕

 One embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, the upper cover 2 fixed to the inner peripheral wall of the casing and the rotating shaft 3 inserted through the center of the upper cover 2
And a tubular stationary outer ring 4 having an end surface on one side (lower side) fixed to the upper cover 2 and an outer circumference on the other end (upper side) of the stationary outer ring 4. The stationary side sub-sealing ring 8 which is fixed to
And the stationary side sub-sealing ring 8 which is slidably contacted in the axial direction through the water sealing material 9 provided on the inner peripheral surface of the stationary side sub-sealing ring 8 and is substantially concentric with the rotary shaft 3 through the gap 29. Ring 10 and stationary inner ring 10
Static seal ring 11 attached to one end (lower side) end face
A rotary side sealing ring 13 which is in sliding contact with the stationary side sealing ring 11 to form a sealing end face 12 and which is attached to one side (lower side) of the rotating shaft 3, and each stationary side outer ring 4 and a stationary side. Sub sealing ring 8,
In a shaft sealing device for a fluid machine, which comprises a stationary side inner ring 10, a stationary side sealing ring 11, and a sealing chamber 14 surrounded by a rotating side sealing ring 13, a bearing fixed to the other side (upper side) of the rotating shaft 3. Support ring
A pressing mechanism is provided between the support ring 21 that contacts the other end (lower side) of the stationary inner ring 10 and the pressing mechanism slides through the bearing support ring 28 and a bearing (thrust bearing). An elastic mechanism (spring) 18 is provided which comes into contact freely and presses the stationary side inner ring 10 via the support ring 21 to press the stationary side seal ring 11 against the rotating side seal ring 13.

The pressing mechanism includes a slide ring 16 slidably contacting the bearing 15, and a support ring 16 facing the slide ring 16 and contacting the other end surface (upper side) of the stationary inner ring 10. 21 and sliding ring
At least one piston 17 having one end fixed to 16 and the other end attached to a support ring 21 via an elastic mechanism (spring) 18;
It is configured by adjusting mechanisms 19 and 20 for adjusting the biasing force of the elastic mechanism 18.

Further, the elastic mechanism may be a spring 18 and may be a hydraulic cylinder, a hydraulic cylinder or a gas cylinder.

With this configuration, when the deflection angle θ is generated during the operation of the fluid machine, the stationary sub-sealing ring 8 is correspondingly generated.
Slides on the upper side through the sealing material 9 and does not affect the stationary side inner ring 10. As a result, the stationary side seal ring 11 is pressed against the rotating side seal ring 13 via the stationary side inner ring 10 by the pressing mechanism provided on the stationary side inner ring 10, and the stationary side ( It is possible to obtain a shaft water sealing device for a fluid machine that is not affected by displacement (deflection) on the fixed portion side or axial displacement on the rotating side, and that is capable of preventing the surface pressure change of the sealed end face.

That is, a bearing support ring 28 and a thrust bearing 15 are provided on the rotary shaft 3, and the bearing 15 is slidably in contact with the stationary side seal ring 11.
The stationary side inner ring 10
Although it is provided on the upper part of the sliding ring 16, the pressing mechanism slidably contacts the bearing 15, the piston 17 provided on the sliding ring 16 in parallel with the rotary shaft 3, and the lower part of the piston 17. And a supporting ring 21 that is attached to the stationary side inner ring 10 and is surrounded by the springs 18 and the piston 17 on the lower side thereof.
And a spring retainer fitting 20 that covers the lower side of the support ring 21 and that has an adjusting bolt 19. In addition, support bracket 2
2, 23 are shown.

The stationary side inner ring 10 is connected to the stationary side sub-sealing ring 8 via the key 30.
The rotation is locked. By doing so, even if the fixed part side or the rotating part side is displaced due to pressure fluctuations on the flow path side, the stationary side seal ring 11 is provided with the bearing 15 and the support ring 21 by the pressing mechanism provided on the stationary side inner ring 10. It is pressed against the sealing end surface 12 of the rotary side sealing ring 13 via. Further, a water sealing material 9 is arranged between the stationary side inner ring 10 and the stationary side auxiliary sealing ring 8, and the stationary side auxiliary sealing ring 8 is formed so as to slide in the axial direction between the stationary side auxiliary sealing ring 8 and the water sealing material 9. Therefore, the displacement on the fixed portion side or the rotating portion side does not affect the surface pressure of the sealed end face 12.

By providing the pressing mechanism in this way, the pressure in the sealing chamber 14 does not affect the surface pressure of the sealing end surface 12, and therefore the surface pressure applied to the sealing end surface 12 can be reduced, so that the elasticity of the spring 18 or the like is reduced. The mechanism allows sufficient sealing performance to be applied regardless of pressure. Further, since it is formed so that the surface pressure of the sealed end face 12 does not change even when the fixed portion side or the rotating portion side is displaced, it is applicable regardless of the size of the fluid machine.

Further, in this embodiment, the sealed chamber 14 is penetrated through the stationary outer ring 4 and from the liquid supply device (not shown) via the pipe 24.
A liquid passage 25 for supplying a liquid is provided. By doing so, it becomes possible to supply the liquid into the sealed chamber 14 from the liquid supply device through the pipe 24 and the liquid passage 25 during the idling operation such as the dry operation, the standby operation, and the pump start-up. It is possible to prevent temperature rise due to sliding friction of 12.

In the case of a pump turbine, when the pump is started, the water in the runner portion is pushed down by compressed air to the downstream side, and the surroundings of the runner are filled with compressed air. Next, rotate the runner, and when the specified rotation is reached, remove air and fill the sealed chamber with liquid,
Although pumping is started, when the surrounding of the runner is filled with compressed air, the sealed chamber becomes air, and therefore the liquid is supplied through the liquid passage 25 at a higher pressure due to the pressure of the compressed air. Stop supplying liquid for sealing when water comes in.

Further, in this embodiment, the rotary shaft 3 which penetrates the stationary inner ring 10 and communicates with the fresh water supply device (not shown) to the sealed end face 12 side.
A cleaning liquid passage 27 for supplying fresh water through a pipe 26 is provided in a space between the stationary inner ring 10 and the stationary inner ring 10. By doing so, when contaminated water or the like is used, it becomes possible to supply clean water from the clean water supply device to the gap between the rotary shaft 3 and the stationary side seal ring 11 through the pipe 26 and the cleaning liquid passage 27. By doing so, it is possible to discharge stagnant substances and adhered substances in the gap between the rotary shaft 3 and the stationary side seal ring 11 to the outside of the shaft sealing device, and these parts can be washed to prevent corrosion, stagnant substances and It is possible to prevent the sealing performance from deteriorating due to deposits and the like. Further, when used in a device for contaminated water as described above, since the portion in contact with contaminated water has a simple structure, anticorrosion measures can be easily performed.

〔The invention's effect〕

According to the present invention, by providing the pressing mechanism in the shaft water sealing device for a fluid machine, even if the upper cover or the rotating shaft is displaced in the axial direction by the pressure of the fluid, the surface pressure of the sealing end face does not decrease, and the sealing is performed. The liquid in the chamber never leaks.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIGS. 2 and 3 are sectional views showing a conventional technique. 2 ... Top cover, 3 ... Rotation axis, 4 ... Stationary outer ring, 8
...... Stationary side sub-sealing ring, 9 ...... Water sealing material, 10 ...... Stationary side inner ring, 11 ...... Stationary side sealing ring, 12 ...... Sealing end face, 13 ...... Rotating side sealing ring, 15 ...... Bearing, 16 …… Sliding ring, 17 …… Piston, 18 …… Spring (elastic mechanism), 19 …… Adjustment bolt (Adjustment mechanism), 20 …… Spring retainer (Adjustment mechanism), 21 …… Support ring.

Claims (5)

(57) [Claims] 1. A tubular stationary side provided in an annular space between an upper cover fixed to an inner peripheral wall of a casing and a rotary shaft inserted through the center of the upper cover, and having one end face fixed to the upper cover. An outer ring, a ring-shaped stationary side sub-sealing ring whose outer circumference is fixed to the other end surface of the stationary side outer ring, and an inner circumference of which is concentric with the rotating shaft; A stationary side inner ring that is slidably contacted in the axial direction via a water sealing material provided on the peripheral surface and is concentric with the rotating shaft via a gap, and an end surface of one side of the stationary side inner ring A stationary side sealing ring, a rotating side sealing ring that is in sliding contact with the stationary side sealing ring to form a sealing end face and is mounted on one side of the rotating shaft, and a stationary side outer ring and a stationary side. A shaft sealing device for a fluid machine comprising a sub-sealing ring, a stationary inner ring, a stationary chamber surrounded by a stationary sealing ring and a rotating sealing ring. , A pressing mechanism is provided between a bearing support ring fixed to the other side of the rotary shaft and a support ring that contacts the other end surface of the stationary side inner ring, and the pressing mechanism includes the bearing support ring and the bearing. The fluid machine is provided with an elastic mechanism that slidably contacts with the stationary side inner ring via the support ring and presses the stationary side seal ring against the rotating side seal ring. Shaft water seal device. 2. The pressing mechanism includes a slide ring slidably contacting a bearing, a support ring facing the slide ring and contacting an end face on the other side of the stationary side inner ring, It comprises at least one piston, one end of which is fixed to the sliding ring and the other end of which is attached to the support ring via an elastic member, and an adjusting mechanism which adjusts the biasing force of the elastic mechanism. Item 1. A shaft water sealing device for a fluid machine according to item 1. 3. The shaft sealing device for a fluid machine according to claim 1, wherein the elastic mechanism is a spring. 4. The shaft water sealing device for a fluid machine according to claim 1, wherein the elastic mechanism is a hydraulic cylinder. 5. The shaft water sealing device for a fluid machine according to claim 1, wherein the elastic mechanism is a hydraulic cylinder.